Remarkable progress has been made in deriving functional cardiomyocytes from human stem cells, and developing tissue-engineering strategies for utilization of these cells. However, the survival and function of cardiac grafts remain poor, for at least two reasons: tissue-engineering strategies do not provide the necessary cell protection and conditioning, and the ischemic/inflammatory environment of the injured heart is completely overlooked. We postulate that some of the existing barriers to the development of effective cell therapies for myocardial infarction can be overcome by manipulating cell coupling in the graft at the time of implantation and graft interactions with the host environment. To tackle such a highly interdisciplinary problem, we formed an association of two laboratories providing strong expertise in cardiac tissue engineering (Columbia University) and analysis of inflammatory responses (Albert Einstein College of Medicine). Over the last six months, we conducted extensive preliminary studies to formulate a working hypothesis, develop the investigational approach, and demonstrate feasibility of key experimental methods. Cardiac tissue grafts will be grown from human iPS-derived cardiomyocytes, with electrical stimulation, and in the presence of inflammatory cytokines. We designed a 3D human tissue platform with critical components of the inflammatory environment, application of electrical stimulation and capability for functional imaging, in a convenient 96-well format. This platform will be validated using an animal implantation model of cardiac infarction. Our working hypothesis is that the multidimensional interplay between cardiac cells, inflammatory cells and cytokines can be therapeutically skewed to maximize graft survival and function. In Aim 1, we will characterize the responses of cardiac grafts to inflammatory cytokines and hypoxia, and evaluate the effects of graft conditioning by cell-protective cytokines. In Aim 2, we will evaluate engineered cardiac grafts in an animal model of acute cardiac ischemia. Our long-term goal is to identify cardio-protective measures leading to improved survival and function of cardiac grafts following their implantation into the infarct bed. (End of Abstract)